The present invention relates to a battery cell comprising a prismatically-designed cell housing having a cover surface, on which a negative terminal and a positive terminal are arranged, and at least one electrode coil arranged within the cell housing and having a cathode, which has cathode contact lugs, and having an anode, which has anode contact lugs. The invention also relates to a battery system comprising at least one battery cell according to the invention.
It is evident that, in the future, whether in stationary applications such as wind turbine installations, in motor vehicles which are configured as hybrid vehicles or electric vehicles, or in electronic devices such as laptop computers or mobile phones, new battery systems will be employed which will be subject to very stringent requirements with respect to reliability, safety, performance capability and service life.
So-called Lithium-ion battery cells are specifically employed for this purpose. These are characterized, amongst other features, by high energy densities, thermal stability and extremely low self-discharge capability. Lithium-ion battery cells have a positive and a negative electrode upon which, during a charging process and also during a discharging process, lithium ions can be reversibly deposited and also released again. A process of this type is also described as intercalation/deintercalation.
In general, a battery cell comprises one or more electrode units, which are configured in the form of a coil. An electrode unit incorporates two foil-type electrodes, namely an anode and a cathode. The electrodes are wound, with the interposition of a separator, to form an electrode coil, which is also described as a jelly-roll. The two electrodes in the electrode coil are electrically connected to the poles of the battery cell, which are also described as terminals, by means of collectors.
A battery cell further comprises a cell housing which is comprised, for example, of aluminum. The cell housing is generally configured as a prism, specifically as a cuboid, and is of pressure-resistant design. Further to the connection of the electrodes to the terminals, the cell housing is filled with an electrolyte solution.
A generic battery cell with an electrode coil is known from EP 2 675 000 A1. The anode and the cathode project from opposing sides of the electrode coil, parallel to the winding axis, and are each connected to a collector. The two collectors are oriented essentially perpendicularly to the winding axis of the electrode coil, and connect the anode and the cathode to the terminals.
A further generic battery cell is known from US 2010/0028770 A1. The electrodes of the electrode coil have contact lugs which project from the electrode coil and are connected to collectors. Prior to the connection with the collectors, the contact lugs are of different lengths.
For the electrical insulation of the electrodes and the cell housing, insulators are provided which are, for example, of plastic construction. An electrode coil with corresponding insulators for a battery cell is disclosed in US 2013/0288092 A1.
Lithium-ion battery cells are relatively sensitive to environmental influences, specifically to air and humidity. The aforementioned cell housing provides protection against said environmental influences. A plurality of such battery cells can be combined to form a battery system, which is also described as a battery pack.